1. Field
This disclosure relates to the field of communication technologies, and in particular to a measurement method and apparatus for a residual direct-current component of an optical transmitter and a system.
2. Description of the Related Art
In an optical communication system, direct-current components of an optical transmitter will result in a relatively large cost on final signal recovery and communication quality after passing through transmission links and being processed by an optical receiver. And as improvement of a communication rate and complexity of a network state, influence of such a cost will become more and more prominent.
In the prior art, the direct-current components of the optical transmitter may be reduced as possible by flexibly configuring a bias of a modulator of a coherent transmitter, thereby lowering the influence of the direct-current components of the optical transmitter (Reference Document 1). However, residual direct-current components always exist, whatever any transmitter configuration method is used. On the one hand, communication quality will be degraded. And on the other hand, as sizes of the residual direct-current components of the optical transmitter are unknown, it is possible that a diagnosis error may occur in surveillance and diagnosis of a communication network, thereby resulting in impropriety of countermeasures, and affecting the performance of the communication system.
Reference Document 1: US20140308047A1.
It should be noted that the above description of the background is merely provided for clear and complete explanation of this disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of this disclosure.